• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.123-135
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• 2012

Purpose: It is essential to minimize the movement of tumor due to respiratory movement at the time of respiration controlled radiotherapy of non-small cell lung cancer patient. Accordingly, this Study aims to evaluate the usefulness of restricted respiratory period by comparing and analyzing the treatment plans that apply free and restricted respiration period respectively. Materials and Methods: After having conducted training on 9 non-small cell lung cancer patients (tumor n=10) from April to December 2011 by using 'signal monitored-breathing (guided- breathing)' method for the 'free respiratory period' measured on the basis of the regular respiratory period of the patents and 'restricted respiratory period' that was intentionally reduced, total of 10 CT images for each of the respiration phases were acquired by carrying out 4D CT for treatment planning purpose by using RPM and 4-dimensional computed tomography simulator. Visual gross tumor volume (GTV) and internal target volume (ITV) that each of the observer 1 and observer 2 has set were measured and compared on the CT image of each respiratory interval. Moreover, the amplitude of movement of tumor was measured by measuring the center of mass (COM) at the phase of 0% which is the end-inspiration (EI) and at the phase of 50% which is the end-exhalation (EE). In addition, both observers established treatment plan that applied the 2 respiratory periods, and mean dose to normal lung (MDTNL) was compared and analyzed through dose-volume histogram (DVH). Moreover, normal tissue complication probability (NTCP) of the normal lung volume was compared by using dose-volume histogram analysis program (DVH analyzer v.1) and statistical analysis was performed in order to carry out quantitative evaluation of the measured data. Results: As the result of the analysis of the treatment plan that applied the 'restricted respiratory period' of the observer 1 and observer 2, there was reduction rate of 38.75% in the 3-dimensional direction movement of the tumor in comparison to the 'free respiratory period' in the case of the observer 1, while there reduction rate was 41.10% in the case of the observer 2. The results of measurement and comparison of the volumes, GTV and ITV, there was reduction rate of $14.96{\pm}9.44%$ for observer 1 and $19.86{\pm}10.62%$ for observer 2 in the case of GTV, while there was reduction rate of $8.91{\pm}5.91%$ for observer 1 and $15.52{\pm}9.01%$ for observer 2 in the case of ITV. The results of analysis and comparison of MDTNL and NTCP illustrated the reduction rate of MDTNL $3.98{\pm}5.62%$ for observer 1 and $7.62{\pm}10.29%$ for observer 2 in the case of MDTNL, while there was reduction rate of $21.70{\pm}28.27%$ for observer 1 and $37.83{\pm}49.93%$ for observer 2 in the case of NTCP. In addition, the results of analysis of correlation between the resultant values of the 2 observers, while there was significant difference between the observers for the 'free respiratory period', there was no significantly different reduction rates between the observers for 'restricted respiratory period. Conclusion: It was possible to verify the usefulness and appropriateness of 'restricted respiratory period' at the time of respiration controlled radiotherapy on non-small cell lung cancer patient as the treatment plan that applied 'restricted respiratory period' illustrated relative reduction in the evaluation factors in comparison to the 'free respiratory period.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.807-820
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• 2023

Objective: To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. Materials and Methods: This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1-7 according to acquisition conditions. CT images in groups 2-7 were converted into the target CT style (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. Results: Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2-7 improved after CT conversion (original vs. converted: 0.63 vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists' scores were significantly higher (P < 0.001) and less variable on converted CT. Conclusion: CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

• Journal of Trauma and Injury
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• v.33 no.2
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• pp.88-95
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• 2020

Purpose: The present study will identify risk factors for aspiration in severe trauma patients by comparing patients who showed a sign of aspiration lung disease on chest computed tomography (CT) and those who did not. Methods: We conducted a retrospective review of the Korean Trauma Data Bank between January 2014 and December 2019 in a single regional trauma center. The inclusion criteria were patients aged ≥18 years with chest CT, and who had an Injury Severity Score ≥16. Patients with Abbreviated Injury Scale (AIS)-chest score ≥1 and lack of medical records were excluded. General characteristics and patient status were analyzed. Results: 425 patients were included in the final analysis. There were 48 patients showing aspiration on CT (11.2%) and 377 patients showing no aspiration (88.7%). Aspiration group showed more endotracheal intubation in the ER (p=0.000) and a significantly higher proportion of severe Glasgow Coma Scale (GCS) (p=0.000) patients than the non-aspiration group. In AIS as well, the median AIS head score was higher in the aspiration group (p=0.046). Median oxygen saturation was significantly lower in the aspiration group (p=0.002). In a logistic regression analysis, relative to the GCS mild group, the moderate group showed an odds ratio (OR) for aspiration of 2.976 (CI, 1.024-8.647), and the severe group showed an OR of 5.073 (CI, 2.442-10.539). Conclusions: Poor mental state and head injury increase the risk of aspiration. To confirm for aspiration, it would be useful to perform chest CT for severe trauma patients with a head injury.

• Journal of Yeungnam Medical Science
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• v.27 no.1
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• pp.57-62
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• 2010

Pulmonary alveolar proteinosis (PAP) is a rare disorder that's characterized by accumulation of surfactant components in the alveolar space. Idiopathic PAP is recognized as an autoimmune disease that's due to impaired alveolar macrophage function and this caused by autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). We report here a case of pulmonary alveolar proteinosis that was deemed interstitial lung disease at the initial diagnosis. A 61-year-old man presented with intermittent blood tinged sputum and dyspnea on exertion. The man was a painter for 30 years and he had a 10 pack-years smoking history. Chest computerized tomography (CT) revealed multifocal ground-glass opacity with interstitial thickening at both lungs. His pulmonary function tests and methacholine test revealed non specific results. He was diagnosed with interstitial lung disease on the basis of the chest CT finding and occupational history. However, seven months later, his symptoms progressed. Follow-up chest CT was performed. Wedge resection via video-assisted thoracoscopic surgery (the anterior basal segment of the left lower lobe) was done. Microscopic examination showed large groups of alveoli with excessive amounts of surfactant and a complex mixture of protein and lipid (fat) molecules. Finally, he was diagnosed as having pulmonary alveolar proteinosis.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.123-130
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• 2007

The aim of this study was to propose a fusion and registration method with heterogeneous small animal acquisition system in small animal in-vivo study. After an intravenous injection of $^{18}F$-FDG through tail vain and 60 min delay for uptake, mouse was placed on an acryl plate with fiducial markers that were made for fusion between small animal PET (microPET R4, Concorde Microsystems, Knoxville TN) and Discovery LS CT images. The acquired emission list-mode data was sorted to temporally framed sinograms and reconstructed using FORE rebining and 2D-OSEM algorithms without correction of attenuation and scatter. After PET imaging, CT images were acquired by mean of a clinical PET/CT with high-resolution mode. The microPET and CT images were fusion and co-registered using the fiducial markers and segmented lung region in both data sets to perform a point-based rigid co-registration. This method improves the quantitative accuracy and interpretation of the tracer.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.23-27
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• 2006

Purpose: There are a few case reports on asymmetric vocal cord uptake on FDG-PET in patients with unilateral vocal cord paralysis, which could be a potential pitfall in the interpretation of FDG-PET images. We evaluated the metabolic activity of laryngeal muscles of patients with unilateral vocal cord paralysis in comparison to normal controls during both speech and silence. Methods: Eleven patients with unilateral vocal cord palsy (thyroldectomy=7, lung cancer=1, others=3) and 12 normal controls underwent FDG-PET with usual protocol. They were divided into two groups respectively; one group read books aloud for 20 minutes (phonation group) and the other kept silence (non-phonation groups) after FDG injection. Recent neck CT scan were co-registered with FDG-PET to produce PET-CT fusion images to elaborate small laryngeal muscles. Results: In patients with unilateral vocal cord palsy, contralateral non-paralyzed vocal cord showed hypermetabolism mainly on thyroarytenoid muscle, more intensely with phonation group ($SUV=5.88{\pm}2.65$) than with non-phonation group ($SUV=2.30{\pm}0.39$). Normal control subjects showed hypermetabolism ($3.68{\pm}0.96$) in interarytenoid muscle and symmetric mild hypermetabolism in both lateral cricoarytenoid muscles in only phonation group. Conclusion: FDG-PET with fusion images using CT scan in patients with unilateral vocal cord paralysis showed hypermetabolism of contralateral non-paralyzed thyroarytenoid muscle, suggesting compensatory action during phonation. Phonation durung FDG PET study enhanced FDG uptake on different laryngeal muscles between patients with unilateral vocal cord paralysis and normal subjects.

• Journal of KIISE:Software and Applications
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• v.33 no.11
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• pp.942-952
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• 2006

We propose an automatic segmentation method for identifying pulmonary structures using gray-level information of chest CT images. Our method consists of following five steps. First, to segment pulmonary structures based on the difference of gray-level value, we select the threshold using optimal thresholding. Second, we separate the thorax from the background air and then the lungs and airways from the thorax by applying the inverse operation of 2D region growing in chest CT images. To eliminate non-pulmonary structures which has similar intensities with the lungs, we use 3D connected component labeling. Third, we segment the trachea and left and right mainstem bronchi using 3D branch-based region growing in chest CT images. Fourth, we can obtain accurate lung boundaries by subtracting the result of third step from the result of second step. Finally, we select the threshold in accordance with histogram analysis and then segment radio-dense pulmonary vessels by applying gray-level thresholding to the result of the second step. To evaluate the accuracy of proposed method, we make a visual inspection of segmentation result of lungs, airways and pulmonary vessels. We compare the result of the conventional region growing with the result of proposed 3D branch-based region growing. Experimental results show that our proposed method extracts lung boundaries, airways, and pulmonary vessels automatically and accurately.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.284-292
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• 2019

To evaluate the usefulness of pediatric chest CT scans by comparing the dose, examination time, and image quality by applying Helical mode, High-pitch mode, and Volume Axial mode to minimize the radiation exposure and obtain high diagnostic value. Revolution (GE Healthcare, Wisconsin USA) was used to divide PBU-70 phantom into Helical mode, High-pitch mode, and Volume Axial mode. After acquiring images, ROI is set for each image, heart, bone, lung, and back-ground air, and the average value is obtained by measuring CT number (HU) and noise (SD). SNR and CNR were measured and compared with DLP values provided directly by the equipment. Determining statistical significance Statistical analysis was performed using ONE-WAY-ANAOVA using SPSS 21.0. In this experiment, it was possible to inspect at a short time without deterioration of image quality with the lowest dose when using volume axial mode. Although the detector coverage of 16 cm is limited to all pediatric chest CT scans, it is recommended to be actively used in pediatric patients, and further study is needed to apply other test sites in volume axial mode.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.226-230
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• 1997

This is a case report of surgical management of a bilateral intralobar pulmonary sequestration with horseshoe lung presenting with frequent U I with productive sputum. Simple chest X-ray showed pneumonic consolidation and infiltration on both lower lobes, and chest CT revealed multiple cystic lesions compatible with pulmonary sequestration. The aortography demonstrated two anomalous systemic arteries arising from the thoracic aorta just above the diaphragm to both sequestrums. Left lower lobectomy was performed through the left thoracotomy with ligations and divisions of the both systemic feeding arteries to the left and right sequestrum, and division of the isthmic portion of horseshoe lung without removal of right sequestrum. The patient was discharged on the postoperative loth day and followed-up till now without any sequelae and symptoms of residual right sequestration. The recent follow-up chest CT 5 months after the operation revealed spontaneous regression of the residual right sequestrum. Authors would suggested that only division of aberrant artery to sequestrum without lobectomy may be applied in uncomplicated ca e of intrapulmonary seqilestration.

• Korean Journal of Head & Neck Oncology
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• v.16 no.2
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• pp.216-219
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• 2000

Small cell carcinoma usually occurs in lung, but extrapulmonary small cell carcinomas can occur in any sites of body. Most sites of extrapulmonary small cell carcinoma reported were esophagus. And small cell carcinomas occurred in head and neck area were reported rarely. Extrapulmonary small cell carcinoma could be diagnosed when there is no evidence of primary lung lesion on chest X-ray, CT scan of chest and bronchoscopy. The authors experienced a case of small cell carcinoma of left submandibular lymph node in 64-year-old male patient. Biopsy specimen showed poorly differentiated carcinoma but immunohistochemical study showed small cell carcinoma. The chest X-ray and CT scan of chest showed no evidence of primary lung lesion. The patient received chemotherapy(etoposide plus cisplatin) and concurrent chemoradiotherapy using weekly taxol which resulted in good clinical remission. He is still alive 8 months after diagnosis without evidence of lung disease. We report our case with a brief review of literatures.